Our Brains May be 100 Times More Powerful Than We Thought

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The human brain is so powerful that some intelligent
computers called neural networks are patterned after how the human
brain works. As such, figuring out how the many processes of the brain work
continues to be the subject of much research.

A recent study published in the journal Science by
a team of researchers from the University of California Los Angeles (UCLA)
has uncovered new information about the brain’s inner workings, and it could
change our understanding of how learning happens.

The study focused on a particular part of neurons, called dendrites.
Dendrites are long
and branch-like structures that connected to the roundish
cell body, called the soma. Dendrites were thought to serve only
as conduits that transfer spikes of electrical activity from the cell
body to other neurons. The UCLA study, however, found that dendrites may
actually be generating their own electrical spikes — and at rates 10 times
more frequently than previously thought.

The researchers arrived at this conclusion by studying mice. Instead of
implanting electrodes into dendrites themselves, they put them next to
dendrites. They found that dendrites were five times more active than somas
when the rats were asleep, and 10 times more when awake and exploring.

Understanding the
Brain

“A fundamental belief in neuroscience has been that neurons are digital
devices. They either generate a spike or not. These results show that the
dendrites do not behave purely like a digital device. Dendrites do generate
digital, all-or-none spikes, but they also show large analog fluctuations that
are not all or none. This is a major departure from what neuroscientists have
believed for about 60 years.” said Mayank Mehta, the study’s senior author, in a UCLA
press release.

Since dendrites are estimated to make up more than 90 percent of neural
tissue — about 100 times larger in volume compared to somas — this could
mean that the human brain has 100 times more capacity than previously believed.

Ultimately, this research could help medical professionals develop new
ways to treat neurological disorders. The study may also shed a new light how
learning really occurs.

“Many prior models assume that learning occurs when the cell bodies of
two neurons are active at the same time. Our findings indicate that learning
may take place when the input neuron is active at the same time that a dendrite
is active — and it could be that different parts of dendrites will be active at
different times, which would suggest a lot more flexibility in how learning can
occur within a single neuron.” explained author Jason Moore in the press
release.